/Engine/Source/Runtime/Core/Public/Containers/ContainerAllocationPolicies.h
Implements a variant of TInlineAllocator with a secondary heap allocator that is allowed to store a pointer to its inline elements. This allows caching a pointer to the elements which avoids any conditional logic in GetAllocation(), but prevents the allocator being trivially relocatable. All UE4 allocators typically rely on elements being trivially relocatable, so instances of this allocator cannot be used in other containers.
template<uint32 NumInlineElements> class TNonRelocatableInlineAllocator